Chlamydia (genital) - including symptoms, treatment and prevention

Chlamydia is caused by the Chlamydia trachomatis bacterium and is the most common sexually transmissible infection (STI) in Australia.

Chlamydia trachomatis infection (excluding eye infections) is a notifiable condition1

How chlamydia is spread

Chlamydia trachomatis is usually transmitted sexually.

Signs and symptoms of chlamydia

Most people do not have any symptoms and can therefore unknowingly transmit chlamydia to sexual partner/s.

Symptoms may be experienced at different body sites:


  • Change in vaginal discharge
  • Irregular bleeding especially after sex
  • Pelvic pain, including pain during sexual intercourse
  • Stinging or burning when passing urine
  • If left untreated, chlamydia can cause pelvic inflammatory disease (PID) which is an infection of the uterus and fallopian tubes. PID can lead to infertility.


  • Redness at the opening of the penis
  • Stinging or burning when passing urine
  • Discharge from the penis
  • Pain and swelling of the testes.


  • Discharge, pain or bleeding from the anus.


  • Chlamydia can cause conjunctivitis (inflammation of the lining of the eyelids and eye) in both adults and babies. Chlamydia can pass from an infected birth canal during delivery. Infected babies may develop conjunctivitis or pneumonia (lung infection or inflammation).

A small proportion of people infected with Chlamydia trachomatis develop joint pain.

Having chlamydia does not result in immunity, so re-infection is common. It is likely that the most serious complications (infertility, pelvic inflammatory disease) are the result of repeated infections.

Lymphogranuloma venereum

Lymphogranuloma venereum (LGV) is a STI caused by certain strains of the bacterium that causes chlamydia. For more information, see the LGV page .

Diagnosis of chlamydia

Chlamydia can be diagnosed by PCR (polymerase chain reaction) on urine or swabs which can be collected from the vagina, cervix, rectum or throat depending on your sexual activity. Self-collected swabs may be available in some circumstances.

The infection cannot be diagnosed from a blood test.

Incubation period

(time between becoming infected and developing symptoms)

1 to 3 weeks.

Infectious period

(time during which an infected person can infect others)

There is limited information about the infectious period of Chlamydia trachomatis, but people are presumed to be infectious from the end of the incubation period until treatment is completed. If left untreated, the infectious period may last several months.

Treatment for chlamydia

Effective antibiotic treatment is available on prescription from a doctor. However, if infertility develops, there is no simple treatment.

Prevention of chlamydia

  • All sexual partners need to be contacted, tested and treated, if needed. Even if partners have no symptoms they may be able to transmit infection to other sexual partners or reinfect you .
  • Avoid sexual contact until you and infected partners have completed treatment. A follow-up test must be done to make sure that treatment has cured the infection.
  • Testing to exclude other sexually transmitted infections is advisable.
  • Use condoms and other barrier methods to prevent getting sexually transmitted infections, including chlamydia.
  • Get tested for sexually transmitted infections regularly (even if you do not have symptoms), particularly when you have new sexual partners.

Useful links

1 - In South Australia law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.